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Char.IsDigit Method (String, Int32)

Indicates whether the character at the specified position in a specified string is categorized as a decimal digit.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Shared Function IsDigit ( _
	s As String, _
	index As Integer _
) As Boolean

Parameters

s
Type: System.String

A string.

index
Type: System.Int32

The position of the character to evaluate in s.

Return Value

Type: System.Boolean
true if the character at position index in s is a decimal digit; otherwise, false.

ExceptionCondition
ArgumentNullException

s is Nothing.

ArgumentOutOfRangeException

index is less than zero or greater than the last position in s.

This method determines whether a Char is a radix-10 digit. This contrasts with IsNumber, which determines whether a Char is of any numeric Unicode category. Numbers include characters such as fractions, subscripts, superscripts, Roman numerals, currency numerators, encircled numbers, and script-specific digits.

Character positions in a string are indexed starting from zero.

Valid digits are members of the UnicodeCategory.DecimalDigitNumber category.

The following code example demonstrates IsDigit.

Imports System

Module IsDigitSample

    Sub Main()

        Dim ch8 As Char
        ch8 = "8"c

        Console.WriteLine(Char.IsDigit(ch8))                    ' Output: "True"
        Console.WriteLine(Char.IsDigit("sample string", 6))     ' Output: "False" 

    End Sub 

End Module

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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